Sensing switch for a magnetically coupled communications port

ABSTRACT

A magnetically coupled communications port includes a switch for providing an enable signal upon coupling of a detachable magnetic coupler assembly to a fixed coupler assembly. The switch is magnetically activated and is positioned on the fixed coupler assembly in proximity to one end of a cylindrical slug of a magnetically conductive material. The opposite end of the cylindrical slug is positioned co-planar with an external face portion of the fixed coupler assembly. When the detachable magnetic coupler assembly mates with the fixed coupler assembly, contacting the face portion and the co-planar surface of the cylindrical slug, magnetic flux from the detachable magnetic coupler is concentrated through the slug causing the magnetically activated switch to switch from an inactivated position to an activated position.

BACKGROUND OF THE INVENTION

The present invention relates generally to communication coupler devicesand more particularly to such devices having magnetic and opticalcharacteristics which allow mating magnetic couplers to be joined forthe transfer of information between electronic devices.

The present invention is useful in those types of applications where itis desirable or necessary to electronically communicate with electroniccircuitry which is inaccessably housed, such as within a sealedenclosure. To this end, and as a preferred embodiment, the inventionfinds particular application in utility meters of the computerizedelectronically programmable type. These types of meters are mostfrequently designed to be programmed or re-programmed at the place ofinstallation, such as at the customer residence or a commercial businesssite. Ideally, these types of meters are designed for electronic readoutof meter data, for example total kilowatt hour consumption, demandkilowatt consumption and the like.

Programming and reading of the above types of meters is normally done bya utility company meter reader or service person utilizing a portablereader/programmer device. This device is usually provided with some typeof plug device for attachment to the meter to enable thereader/programmer to communicate with the electronics inside the metercover.

The use of an optical coupler for programming meters of the above typeis made attractive because of the economic design and manufacturing costincentives such a coupler affords. A further attractive feature is thehigh reliability of optical emitter and detector devices employed insuch couplers.

One type of optical coupler is shown and described in co-pending U.S.patent application Ser. No. 533,896, which is a continuation of Ser. No.190,217, filed Sept. 24, 1980 now abandoned and which is assigned to theassignee of the present invention and which is incorporated by referencein the present application as if fully set forth herein. That couplercomprises a first coupler assembly which is rigidly mounted through themeter cover and a second coupler assembly which can be magneticallyattached to the first coupler assembly. The coupler is constructed suchthat precise alignment is maintained between the first and secondcoupler assemblies when they are magnetically attached to each otherwhile inhibiting the entry of ambient light from entering between thecoupled portions.

Although the aforementioned magnetic optical coupler provides aneconomical and reliable means for communicating with electronic deviceswhich are sealed within a housing or cover, a need exists for a means ofsignaling the enclosed electronic device that the magnetic coupler hasbeen mated. Such a signal can be used by the enclosed electronic deviceto enable the optical emitter and detector devices as well as to providean indication that communication with an external device through themated coupler is ready to take place. The signaling means should bereliable, tamper resistant, be able to operate through a sealedpartition and have no moving parts exposed outside of the partition.

SUMMARY OF THE INVENTION

The aforementioned needs are satisfied by the present invention by theprovision of a magnetically activated switch assembly. The invention, ina preferred embodiment, is advantageously applied in utility meters ofthe electronically programmable type, which can be externally programmedby a portable reader/programmer device having a coupler which ismagnetically coupled to the utility meter.

In applying the apparatus of the invention, a first coupler assembly ismounted through a meter cover. This first coupler assembly is preferablyfabricated from a magnetically conductive material. The coupler assemblycontains a face portion which is mounted external of the meter cover. Anaperture extends from this face portion into the coupler assembly. Atleast one optical communication means is disposed in the aperture, andis oriented therein to provide a communication path for the opticalcommunication means through the aperture in the face portion of thecoupler assembly. This optical communication means is connected toelectronic circuitry inside the meter cover. A magnetic fluxconcentrator, preferably a cylindrical slug of magnetically conductivematerial, is mounted in the first coupler assembly such that one end ofthe cylindrical slug is positioned substantially flush with the faceportion. The opposite end of the cylindrical slug is positioned adjacenta magnetically activated switching means.

A second coupler assembly is provided for magnetic attachment to thefirst coupler assembly. The second coupler assembly is preferablyconstructed as a magnet having a magnetized surface for mating magneticattachment to the face portion of the first coupler assembly. In amanner similar to the first coupler assembly, the second couplerassembly also contains an aperture extending from its magnetized surfaceinto the body of the second coupler for the containment of a secondoptical communication means. The orientation of the second opticalcommunication means in the aperture of the second coupler assemblyprovides an optical communication path through the aperture for theestablishment of a communication link between the first and secondoptical communication means when the two coupler assemblies aremagnetically coupled. A portable reader/programmer device is connectedto the second optical communication means to complete communication withthe meter electronic circuitry via the mated optical coupler.

When the first and second coupler assemblies are magnetically coupled,the cylindrical magnetically conductive slug will conduct magnetic fluxfrom the magnetized surface of the second coupler assembly to themagnetically activated switch, thereby causing the switch to switch fromits unactivated to its activated position. In the preferred embodiment,the activation of this switch enables the meter electronic circuitry tocommunicate with the portable reader/programmer via the optical coupler.

It is therefore an object of the present invention to provide an opticalcoupling apparatus for the transfer of electronic information whichincludes a device for enabling and inhibiting the transfer ofinformation over the optical link.

It is another object of the present invention to provide a magneticallydetachable optical coupling apparatus characterized by incorporating amagnetically activated switch to enable transfer of information througha communication link established by the coupled apparatus.

A further object of the invention is to provide an optical couplingapparatus which incorporates an enabling switch inaccessably housedwithin an enclosure but which is activatable upon the mating of theoptical link.

Still another object of the invention is to provide a combinationmagnetic and optical coupler apparatus which enables the electroniccommunication between electronic circuitry housed within a sealed coverof a meter and a portable electronic communication device connectedexternal of the meter housing.

It is yet another object of the present invention to provide acombination optical magnetic coupler apparatus including means forenabling optical detector and/or emitter devices to effect uponcoupling, unidirectional or bidirectional communication with anelectronically programmable meter from a reader/programmer deviceconnected external of the meter cover having electronics inaccessablyhoused therein.

A further object of the present invention is to provide a switch meansfor enabling the electronic communication between an electronicallyprogrammable meter and a reader/programmer device connected external ofa meter cover having electronics inaccessably housed therein, saidswitch means having no moving parts exposed outside of the cover.

Still a further object of the present invention is to provide areliable, tamper resistant means of enabling communication between anelectronically programmable meter and a reader/programmer deviceconnected external of the meter cover having electronics inaccessablyhoused therein.

These and other objects, features and advantages of the presentinvention will become more fully apparent from the following detaileddescription of the preferred embodiment, the appended claims and theaccompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a functional block diagram depicting the flow of informationbetween a reader/programmer device and an electronically programmablemeter through a magnetic optical coupler incorporating a coupler sensingswitch of the present invention.

FIG. 2 is a side view, partly in cross-section, of a second couplerassembly of the present invention.

FIG. 3 is an end view, partly in cross-section, showing a portion of thesecond coupler assembly of FIG. 2 looking into the left side thereof.

FIG. 4 is an end view showing a portion of the second coupler assemblyof FIG. 2 looking into the right side thereof.

FIG. 5 depicts a terminal block having a magnetically activated switchmounted thereon.

FIG. 6 is a side view, partly in cross-section, showing first and secondcoupler assemblies magnetically coupled for operation.

FIG. 7 is an end view showing a face portion of the first couplerassembly.

FIG. 8 is an end view showing a rear portion of the first couplerassembly.

FIG. 9 is an electrical schematic showing the wiring of opticalcommunication devices used in each of the first and second couplers ofthe present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1, there is shown a functional block diagramillustrating the flow of information between an electronicallyprogrammable meter, generally designated 10 and a portablereader/programmer device, generally designated 12. The electronicallyprogrammable meter includes a microprocessor 14 for receiving,processing and outputting data. The meter also includes a data sourceselector 16 for selecting one of at least two meter communication paths.As shown in FIG. 1, these communication paths are between either acentral data acquisition and transmission system (not shown), via atelephone line modem 18, or the portable reader programmer device 12 viaan optical coupler generally designated 20, having a fixed couplersegment 22 sealably mounted through a meter cover or housing (not shown)preferably in accordance with the teachings of the aforementioned U.S.patent application Ser. No. 533,895.

When the data source selector 16 selects the telephone modem 18,outbound data from the meter 10 flows to the modem 18 by way of atransmit data (XMIT DATA) path 24. Inbound data flows from the telephonemodem 18 to the data source selector 16 by way of a first inbound datapath 26. In this mode of communication, the data source selector 16transmits the inbound data from the first inbound data path 26 to themicroprocessor 14 over a receive data (RCV DATA) path 28.

When communicating with the programmer/reader device 12, outbound dataflows from the microprocessor 14 over the XMIT DATA path 24, through thedata source selector 16, over an outbound data path 29 to a lightemitting diode (LED) transmitter 30 which is mounted within the fixedcoupler segment 22 of the magnetic optical coupler 20, as shown anddescribed in the aforementioned U.S. patent application Ser. No.533,895. In this mode of communication, inbound data flows from aphotocell receiver 32, which is housed within the fixed coupler segment22 of the optical coupler 20, as shown and described in theaforementioned U.S. patent application, to the data source selector 16by way of a second inbound data path 34. The data source selector 16transmits the data from the second inbound data path 34 to themicroprocessor 14 over the RCV DATA path 28.

The reader/programmer device 12, is electrically connected to adetachable magnetic coupler segment 36 of the optical coupler 20. Thedetachable magnetic coupler segment 36 is adapted to mate with andmagnetically couple to the fixed coupler segment 22 of the opticalcoupler 20. The detachable magnetic coupler segment 36 includes a lightemitting diode (LED) transmitter 38 which receives a data signal fromthe reader/programmer device 12 over an outbound data path 40. Thedetachable magnetic coupler segment 36 also includes a photocellreceiver 42 which emits data signals to the reader/programmer device 12over the inbound data path 44. The LED transmitter 38 and the photocellreceiver 42 are mounted in the detachable magnetic coupler segment 36preferably in the manner shown and described in the aforementioned U.S.patent application Ser. No. 533,895.

The fixed coupler segment 22 of the optical coupler 20 also includes amagnetically operated switching means 46 which is activated uponmagnetically coupling the detachable magnetic coupler segment 36 to thefixed coupler segment 22 as will be hereinafter described. Thedetachable magnetic coupler segment 36 also includes a device activateswitch means 48 which is operated upon mating the detachable magneticcoupler segment 36 to the fixed coupler segment 22 as will behereinafter described.

Upon activation, the magnetically operated switching means 46 closes andapplies ground to a terminal of the data source selector 16, by way ofinput line 50, causing the selector 16 to switch from the telephonemodem communication paths to the portable reader/programmer devicecommunication paths. The magnetically operated switching means 46 alsoapplies ground to an input of the microprocessor 14, over the input path52, thereby alerting the microprocessor 14 that communication is tooccur between the meter 10 and the portable reader/programmer device 12.Upon operation, the device activate switch means 48 closes therebysignalling the reader/programmer device 12, by way of lines 53, that theoptical link 20 is coupled and communication with the meter 10 canbegin. Such signalling would result in the application of battery powerto the reader/programmer device upon closure of switch 48.

Referring now to FIG. 2, there is shown a cross-sectional side view of apreferred embodiment of the detachable magnetic coupler segment 36 ofthe optical coupler 20. As previously described in connection with FIG.1, the detachable coupler segment 36 is magnetically attachable to themating fixed coupler segment 22. In its broadest context, the detachablecoupler segment 36 may be comprised of a unitary magnet structure. Asshown in FIG. 2, the structure of the coupler segment 36 comprises anon-magnetic body 60, having a face portion 62 preferably symmetricallydesigned to mate with a face portion on the fixed coupler segment 22 aswill be subsequently described. The detachable magnetic coupler segment36 has an aperture 64 extending into a cavity from the face portion ofthe body 60 for the retention of at least one optical communicationdevice 65 (see FIG. 6). If only unidirectional communication is desired,there would be only one optical communication device 65 located withinthe aperture 64 and that device would communicate with a communicationdevice of opposite type in an aperture of the fixed coupler segment 22,which will be subsequently described.

If bidirectional communication is desired, two apertures such as 64' and64", as shown in FIG. 4, are formed in the body 60 to hold opticalcommunication devices of opposite types, such as a light emitting diode(LED) and a phototransistor (not shown). These devices are mountedwithin the body 60 as shown and described in the aforementionedco-pending U.S. patent application Ser. No. 533,895, which applicationhas been incorporated by reference in this application.

Again referring to FIG. 2, a magnet 66 is disposed around a frontannular shoulder portion 68 of the body 60. As shown at 70 in FIG. 2,the magnet 66 is preferably held in place by a suitable cement, such asepoxy to rigidly attach the magnet 66 to the entire structure or body60.

A cover 72, forming a part of the body 60 and magnet assembly 66, isattached to the body 60 by any suitable means such as counter sunkscrews (not shown). The cover 72 is preferably conductively magneticmaterial and serves essentially four purposes. The first of thesepurposes is to provide a partial protective cover for the couplerassembly 36. The second purpose is to provide a light shield, as shownat 74, in the form of a lip extending out over the face portion end ofthe magnet and the body assembly 66 and 60 respectively. Thirdly, thecover 72 provides a second alignment means 76 formed as a flat in theface portion end of the lip of the light shield 74. The alignment means76 is symmetrically formed to co-act with a flat of alignment meanspositioned on a face portion of the fixed coupler segment 22 as will besubsequently described. And fourthly, the cover 72 serves as a returnpath of the magnetic flux, to thus improve the magnet holding force andincrease the magnet retentivity.

The magnetic holding force is further enhanced by a conductive magneticwasher or spacer 92 disposed between the near face of the magnet 66 andcover 72. The washer 92 provides a path for magnetic flux between cover72 and the magnet 66.

A slot 77 (see FIG. 4) is formed in the face portion end of the lip ofthe light shield 74. The slot exposes a part of a face portion 98 of themagnet 66 thereby permitting an end of an iron slug positioned in thefixed coupler segment 22 to make intimate contact with the face portion98 of the magnet 66 when the detachable magnetic coupler segment 36 iscoupled to the fixed segment 22. This intimate contact enhances magneticflux coupling through the slug for operating a magnetic reed switch aswill be subsequently described.

To complete the detachable coupler segment 36 of FIG. 2, a second orrear cylindrical cover 78 is attached to body 60 by three screws 80 (seeFIG. 3) threaded into the body 60. As can be seen in FIG. 2, the purposeof the cover 78 is to protect the wiring extending from componentsmounted inside the coupler 36. One of these components is the deviceactivate switch means 48 comprising a switch 82 which is mounted on amounting plate 84 which in turn is attached to and spaced from body 60using attachment screws 86 and spacers 87. As shown more clearly in FIG.3, the mounting plate 84 is preferably T-shaped with the switch 82mounted near the end of the leg member of the T and the mounting screws86 being inserted through the mounting plate 84 near the ends of thecross member. The switch 82 is preferably a momentary contact form Atype, and is internally spring loaded in the out direction which is off.

A plunger 88 extends through an aperture 90 in the body 60. The plunger88 also extends through an aperture in washer 92 which is disposedbetween the magnet 66 and a shoulder on the body 60. Also extendingthrough the aperture in the washer 92 and surrounding a portion of theplunger 88 is a bearing tube 94. The portion of the plunger 88 which issurrounded by the bearing tube 94 has a smaller diameter than theportion of the plunger 88 which is disposed through the aperture 90 inthe body 60. These differences in diameters form a shoulder in theplunger which is urged against the washer 92 by the spring loaded switchpin 95. When the shoulder of the plunger 88 is urged against the washer92, a portion 96 of the plunger 88 extends beyond the face portion 98 ofthe magnet 66. As will subsequently be described, when the face portion98 of the magnet 66 engages a mating surface on the fixed coupler 20 (asshown in FIG. 5), the extending portion 96 of the plunger 90 will bedepressed into the bearing tube 94, which in turn depresses the switchpin 95 causing the switch 82 to activate. As previously described theactivation of the switch 82 signals the reader/programmer device 12 thatthe fixed coupler 22 and detachable magnetic coupler segments 36 of theoptical coupler 20 have been mated and communication between thereader/programmer device 12 and the programmable meter 10 is enabled.

Referring now to FIG. 6, there is shown, in partial cross-section, apreferred embodiment of the optical link 20 of the present inventioncomprising the detachable magnetic coupler segment 36 in matingengagement with the fixed coupler segment 22. The fixed coupler segment22 extends through and is attached to a cover 100 of the electronicallyprogrammable meter 10. In its broadest context, the fixed couplersegment 22 may be formed as an integral housing, or body generally shownas 102. The structure of the housing 102 is characterized by a body 104having a face portion 106 and further having at least one aperture 108extending from the face portion 106 into the body 104.

As shown in FIG. 6, the aperture 108 contains at least one opticalcommunication means or device 110 mounted within aperture 108 and heldin place by circuit boards 112 and 114. The boards 112 and 114 aredisplaced by two spacers generally shown as 116. The leads of theoptical device 110 are bought through suitable holes in the circuitboard 114 and are soldered to connecting terminals 118. Three conductors120 of a cable 122 are also soldered to the terminal connectors 118. Theentire assembly, comprising the optical device 110 and the circuitboards 112 and 114, is secured in place within a cavity 124 of the body104 by two retaining screws 126 as shown in FIGS. 6 and 8. These screws126 are passed through the spacers 116 and screwed into the body 104through threads (not shown) in the body 104.

In the preferred embodiment where information is to be bidirectionallytransferred, two apertures 108' and 108" are formed in the body 104 (seeFIG. 7). Mounted within these two apertures are associated opticalcommunication devices 110' and 110" shown in FIG. 9 as an emitter, suchas a light emitting diode 110', and a collector, such as a photocell110". FIG. 9 schematically shows the wiring of wires 120 of cable 122for connecting these optical communication devices to the circuit board114 at terminals 118.

The entire fixed coupler segment 22 is rigidly attached to the metercover 100 by a nut 128 screwed onto the body 104 from the inside of themeter cover 100. To protect the inside of the meter from outsideelements (such as moisture and dirt), a gasket 130 is placed on theoutside of the meter cover 100 between the cover 100 and a flat washer132. A component mounting block 134 having a thick portion 136, a thinportion 138 and an aperture 140 (see also FIG. 5) is disposed betweenthe meter cover 100 and the nut 128 with the threaded portion 129 of thebody 104 extending through the aperture 140. A flat washer 142 is placedbetween the nut 128 and the component mounting block 134 to preventdamage to the mounting block 134 as the nut 128 is tightened against it.In a preferred embodiment, the body 104 has an alignment pin 144 (seeFIGS. 7 and 8) in the backside of an annular shoulder 146 which alignswith a mating hole in the meter cover 100 to prevent the fixed couplersegment 22 from turning and insure that the coupler 22 is properlyoriented when installed.

Still referring to FIG. 6, a portion of the body 104 includes a facecover 148, fabricated from a soft iron, magnetically conductivematerial. As shown in FIGS. 6 and 8, this cover 148 is attached to thebody 104 by three screws 150 threaded from the backside of the shoulder146 into the backside of the cover 148. To complete the sealingarrangement of the fixed coupler segment 22, a gasket 152 is interposedbetween the shoulder 146 and the cover 148.

A light path is provided through the cover 148, which has an opening oraperture in the face portion to allow light communication through thefront of the cover with the optical device 110. For protection of theoptical device 110 a transparent cover 154 is disposed within the cover148. The transparent cover 154 is preferably fabricated from a highimpact plastic or glass substance impervious to breakage. The sealingarrangement of the fixed coupler segment 22 is further enhanced by meansof another gasket 156 disposed between the transparent cover 154 and ashoulder on the inside of the cover 148.

As best seen in FIG. 7, the body 104, and the cover 148 forming a partthereof, also includes a first alignment means 158 shown as a flat onthe bottom side of the cover 148. This alignment means 158 is configuredto symmetrically align with the corresponding alignment means 76 on thecover 72 of the detachable magnetic coupler segment 36.

Referring to FIGS. 5 and 6, there is shown the magnetically operatedswitching means 46, which comprises a magnetically activated reed switch160 electrically connected between a first 162 and second 164 terminalposts disposed on the thin portion 138 of the component mounting board134. A pair of conductors 166 of the cable 122 are electricallyconnected to the terminals 162 and 164.

A cylindrically shaped soft iron slug 168 having a threaded end portion170 extends through a threaded aperture in the body 104. The slug 168 isthreaded through the body 104 to a position at which the end of the slug168 extending from the body 104 makes contact with the face portion 98of the magnet 66 of the detachable magnetic coupler segment 36 throughthe slot 77 when the detachable coupler segment 36 has been magneticallycoupled to the fixed coupler segment 22 as shown in FIG. 6. The magneticreed switch 160 is mounted on the thin portion 138 of the mounting block134 in a position such that when the block 134 is assembled to the body104, the magnetic reed switch 160 is positioned in close proximity tothe other end of the iron slug 168 as shown in FIG. 6.

The purpose of the aforementioned adjustment of the iron slug 168 andthe positioning of the magnetic reed switch 160 with respect to the ironslug 168 is as follows. When the detachable magnetic coupler segment 36is magnetically coupled to the fixed coupler segment 22 as shown in FIG.6, the soft iron slug 168 will conduct magnetic flux from the magnet 66of coupler segment 36 to the reed switch 160, causing the reed switch toactivate. The flux coupling from the magnet 66 to the reed switch 160 isenhanced because one end of the iron slug 168 makes contact with faceportion 98 of the magnet 66 through the slot 77 in the face portion endof the lip of the light shield 74 of the cover 72 as previouslydescribed. The reed switch 160, which in the preferred embodiment isnormally open, is therefore closed by this magnetic flux and held closedas long as the detachable coupler segment 36 is attached to the fixedcoupler segment 22. When the detachable coupler segment 36 is detachedfrom the fixed coupler segment 11, the reed switch 160 will open becauseof the absence of magnetic flux.

This magnetic switch will operate satisfactorily through a steel cover100 as well as covers made of nonmetallic material. However, when usedwith a steel cover, a reasonable clearance aperture must be providedbetween the iron slug 168 and the cover 100. Such an aperture is shownin FIG. 6 and designated by the reference numeral 172.

The detachable magnetic coupler segment 36 is electrically connected tothe reader/programmer device 12 by means of a cable 174 as shown in FIG.6. The cable 174 contains the wires 176 which are electrically connectedto the terminals of the switch 82 as well as the wires 178 which areelectrically connected to the optical communication devices 65 by way ofthe terminals 180 mounted on printed circuit board 182. To preventfraying of the wiring on cable 174, a rubber protective grommet 184 ispreferably installed between the body 60 and the cover 78.

The advantages of the present invention are believed to best be realizedby the utilization of a pulse code or binary communication protocolbetween the portable reader/programmer device 12 and the electronicallyprogrammable meter 10. When using such a protocol, the emitter devices(such as diodes 65' and 110') are pulsed by electronic signals fromtheir respective connected electronics to transmit light pulses acrossthe communication link to their corresponding collector devices (such asphototransistors 65" and 110") which in turn convert those light pulsesto electronic pulses for reception by the electronic circuitry to whichthe collector devices are connected.

This type of communication protocol is particularly advantageous whenused with a meter, which is shown in block diagram form as 10 in FIG. 1,which implements a programmable microprocessor 14 which must beinterrogated and programmed by an external device such as the portablereader/programmer device 12. In such a meter, it is important that themicroprocessor 14 know whether it is communicating with the modem 18 orthe reader/programmer device 12. In addition, in order to preventspurious light from being interpreted as programming information priorto mating of the coupler segments 22 and 36 as well as to protect andextend the life of the operational communication devices 110 containedwithin the fixed coupler segment 36, it is necessary that the opticalcommunication devices remain unenergized until mating of the segmentshas occurred. These functions are provided by the magnetically operatedswitch segment 46 which is activated by the magnet 66 of the detachablecoupler segment 36 through the soft iron slug 168 of the fixed couplersegment 22 upon mating of the detachable coupler segment 36 to the fixedcoupler segment 22 as previously described.

In addition, it is important that the reader/programmer device 12 knowsthat the communication link required for communication with theelectronically programmable meter 10 has been properly implemented. This"knowledge" is imparted to the reader/programmer device 12 by means ofthe device activate switch means 48 which closes upon mating of thedetachable coupler segment 36 to the fixed coupler segment 22 aspreviously described.

From the foregoing description of the invention, it will be apparentthat further modifications and alternative embodiments of it may be madewithout departing from its teachings; accordingly, it is our intentionto encompass within the following claims the true spirit and scope ofthe invention.

What we claim is:
 1. A system of the type including a meter havingelectronic circuitry housed within a cover of the meter, the combinationcomprising:(a) a magnetic coupler assembly having a magnetized surfaceon one end thereof and including communication means of a first type forcommunication out of the magnetized surface end thereof; (b) a fixedcoupler assembly of magnetically conductive material mounted through aportion of the meter cover, said fixed coupler assembly having a faceportion external of the meter cover and including:(1) communicationmeans of a second type for communication out of said face portion; (2)means connecting the communication means of said second type to saidelectronic circuitry for communicating therewith; and (3) meansresponsive to the magnetic flux of said magnetized surface for providinga signal to activate said electronic circuitry to permit communicationupon magnetic coupling of said magnetic and fixed coupler assembly; and(c) external communication means connected to the communication means ofsaid first type in said magnetic coupler assembly for communicatinginformation between the electronic circuitry in the meter cover and saidexternal communication means, via the communication means of said firstand second types, when said fixed and magnetic coupler assemblies aremagnetically coupled.
 2. The system in accordance with claim 1 whereinsaid signal providing means of said fixed coupler assembly comprises:(a)means for concentrating magnetic flux from said magnetized surface ofsaid magnetic coupler assembly when said magnetic and fixed couplerassemblies are magnetically coupled; and (b) switch means switchable toan activated position from an unactivated position in response to saidconcentrated magnetic flux.
 3. The system in accordance with claim 2wherein said means for concentrating magnetic flux comprises acylindrical slug of a magnetically conductive material having a firstend which is positioned substantially co-planar with said face portionof said fixed coupler assembly and having a second end, opposite saidfirst end, positioned proximally said switch means.
 4. The system inaccordance with claim 3 wherein said switch means comprises amagnetically operated reed switch.
 5. The system in accordance withclaim 4 wherein the communication means of said first type comprises anoptical communication means of a first type disposed in an apertureextending into said magnetized surface of said magnetic coupler assemblyand the communication means of said second type comprises an opticalcommunication means of a second type disposed in an aperture extendinginto said fixed coupler assembly from the face portion thereof.
 6. Thesystem in accordance with claim 5 wherein one of the opticalcommunication means of said first and second types is a light emittingdiode and the other of said first and second types is a photocell. 7.The system in accordance with claim 6 wherein said fixed couplerassembly further includes a transparent shield on the face portionthereof for protecting the optical communication means disposed in theaperture of said fixed coupler assembly.
 8. Apparatus for establishing acommunication link for the transfer of information comprising:(a) afirst coupler assembly including:(1) a magnet for magnetic attachment toa second coupler assembly, the structure of said magnet beingcharacterized by a cylindrical body having a face portion and beingfurther characterized by an aperture extending from the face portioninto said magnet; and (2) a communication means of a first type disposedwithin the aperture of said magnet; and (b) a second coupler assemblyincluding:(1) a housing of magnetically conductive material, thestructure of said housing being characterized by a cylindrical bodyhaving a face portion substantially symmetrical with the face portion ofsaid first coupler assembly and being further characterized by anaperture extending from the face portion into said body, and positionedtherein to align with the aperture in the face portion of said firstcoupler assembly; (2) a communication means of a second type disposed inthe aperture of said housing for commuuicating with the communicationmeans in said first coupler assembly; (3) means responsive to themagnetic flux of said magnet for providing a signal when the couplerassemblies are magnetically attached and means responsive to the signalfrom said signal providing means for establishing a communication linkfor the transfer of information by activating said communication meansof said second type.
 9. The apparatus in accordance with claim whereinsaid signal providing means of said second coupler assemblycomprises:(a) means for concentrating magnetic flux from said magnet ofsaid first coupler assembly when said first and second couplerassemblies are magnetically attached; and (b) switching means switchableto an activated position from an unactivated position in response tosaid concentrated magnetic flux.
 10. The apparatus in accordance withclaim 9 wherein said means for concentrating magnetic flux comprises acylindrical slug of a magnetically conductive material having a firstend which is positioned substantially co-planar with the face portion ofsaid second coupler assembly and having a second end, opposite saidfirst end, positioned proximally said switch means.
 11. The apparatus inaccordance with claim 10 wherein said switch means comprises amagnetically operable reed switch.
 12. The apparatus in accordance withclaim 11 wherein the communication means of said first type comprises anoptical communication means of a first type and the communication meansof said second type comprises an optical communication means of a secondtype.
 13. The apparatus in accordance with claim 12 wherein said secondcoupler assembly further includes a transparent shield covering theaperture in the face portion of the housing thereof for protecting theoptical communication means disposed in said aperture.
 14. The apparatusin accordance with claim 13 wherein one of said optical communiationmeans of said first and second types is a light emitting diode and theother of said first and second type is a photocell.
 15. In a system forelectronically communicating information, the combination comprising:(a)a sealed enclosure; (b) electronic circuitry disposed inside said sealedenclosure; (c) a fixed coupler assembly rigidly mounted through aportion of said sealed enclosure including,(1) a housing of magneticallyconductive material having an aperture therein opening to the outside ofsaid sealed enclosure, (2) a communication device of a first typedisposed in the aperture of said housing for communication externally ofsaid sealed enclosure, and (3) means responsive to the magnetic flux ofa magnet for providing an enable signal to said electronic circuitry topermit communication upon magnetic attachment of a detachable couplerassembly to said fixed coupler assembly; (d) means for electricallyconnecting the communication device of said first type to saidelectronic circuitry inside said sealed enclosure; (e) a detachablecoupler assembly including,(1) a magnet for magnetic attachment to saidfixed coupler assembly externally of said sealed enclosure, said magnethaving an aperture in one end thereof positioned for alignment with theaperture in the housing of said fixed coupler assembly, (2) acommunication device of a second type disposed within the aperture ofsaid magnet for communication, out the one end thereof, with thecommunication device of the first type, when said fixed and detachablecoupler assemblies are magnetically attached; and (f) externalcommunication means connected to the communication device of said secondtype in said detachable coupler for electroncially communicatinginformation between the electronic circuitry in said sealed enclosureand said external communication means, via the communication devices ofthe first and second types, when said fixed and detachable couplerassemblies are magnetically coupled and said enable signal is provided.16. The system in accordance with claim 15 wherein said enable signalproviding means of said fixed coupler assembly comprises:(a) means forconcentrating magnetic flux from said magnet of said detachable couplerassembly when said detachable and fixed coupler assemblies aremagnetically attached; and (b) switching means switchable to anactivated position from an unactivated position in response to saidconcentrated magnetic flux.
 17. The system in accordance with claim 16wherein said means for concentrating magnetic flux comprises acylindrical slug of a magnetically conductive material having a firstend which is positioned substantially co-planar with an external faceportion of said housing of said fixed coupler assembly and having asecond end, opposite said first end, positioned proximally said switchmeans.
 18. The system in accordance with claim 17 wherein said switchmeans comprises a magnetically operable reed switch.
 19. The system inaccordance with claim 18 wherein the communication means of said firsttype comprises an optical communication means of a first type and thecommunication means of said second type comprises an opticalcommunication means of a second type.
 20. The system in accordance withclaim 19 wherein said fixed coupler assembly further includes atransparent shield on the external face portion of said housing forprotecting the optical communication means disposed in the aperture ofsaid fixed coupler assembly.
 21. The system in accordance with claim 20wherein one of the optical communication means of said first and secondtypes is a light emitting diode and the other of said first and secondtypes is a photocell.
 22. In a meter of the type including electroniccircuitry housed within a meter cover, apparatus for electronicallycommunicating with the electronic circuitry externally of the metercover comprising:(a) a first coupler assembly rigidly mounted through aportion of the meter cover, said fixed coupler assembly including,(1) ahousing of magnetically conductive material, the structure of saidhousing being characterized by a body having a face portion and beingfurther characterized by first and second apertures extending from theface portion of said body into a cavity formed therein, (2) a firstoptical emitter device, (3) a first optical detector device, (4) meansfor mounting said first optical emitter and detector devices in thecavity of said body, whereby said first optical emitter and detectordevices may optically communicate through the first and second aperturesrespectively in the face portion of said body, and (5) means responsiveto the magnetic flux of a magnet for providing an enable signal to saidelectronic circuitry to permit communication upon magnetic attachment ofa detachable coupler assembly to said fixed coupler assembly; and (b)the second coupler assembly including,(1) a magnet for magneticattachment to said first coupler assembly, the structure of said magnetbeing characterized by a body having a face portion substantiallysymmetrical with the face portion of said housing and being furthercharacterized by third and fourth apertures, positioned for symmetricalalignment with said first and second apertures respectively, extendingfrom the face portion of said magnet into a cavity formed therein, (2) asecond optical emitter device, (3) a second optical detector device, and(4) means for mounting said second optical emitter and detector devicesin the cavity of said magnet, whereby said second optical emitter anddetector devices may optically communicate through the third and fourthapertures respectively in the face portion of said magnet; and (c) meanson said first and second coupler assemblies for ensuring alignment ofthe apertures in the face portions of said housing and said magnet,whereby said first optical emitter device in said housing maycommunicate with the second optical detector device in said magnet andsaid first optical detector device in said housing may communicate withsaid second optical emitter device in said magnet, when said first andsecond coupler assemblies are magnetically attached to form an opticalcommunication link for the transfer of information and said enablesignal is provided.
 23. The meter in accordance with claim 22 whereinsaid enable signal providing means of said first coupler assemblycomprises:(a) means for concentrating magnetic flux from said magnet ofsaid second coupler assembly when said first and second couplerassemblies are magnetically attached; and (b) switching means switchableto an activated position from an unactivated position in response tosaid concentrated magnetic flux.
 24. The meter in accordance with claim23 wherein said means for concentrating magnetic flux comprises acylindrical slug of a magnetially conductive material having a first endwhich is positioned substantially co-planar with the face portion ofsaid housing of said first coupler assembly and having a second end,opposite said first end, positioned proximally said switch means. 25.The meter in accordance with claim 24 wherein said switch meanscomprises a magnetically operable reed switch.
 26. In a system of thetype including a meter having electronic circuitry housed within a coverof the meter, the combination comprising:(a) a fixed coupler assembly ofmagnetically conductive material mounted through a portion of the metercover, said fixed coupler assembly having a face portion external of themeter cover and including an aperture extending into said fixed couplerassembly from the face portion, said fixed coupler assembly furtherincluding:(1) an optical communication means of a first type disposed inthe aperture of said fixed coupler assembly for optical communicationexternal of the meter cover at the face portion of said fixed couplerassembly, and (2) means connecting said optical communication means tothe electronic circuitry for electronically communicating therewith; (b)a magnetic coupler assembly having a magnetized surface on one endthereof and including an aperture extending into said magnetic couplerassembly from the magnetized surface, said magnetic coupler assemblyfurther including:(1) an optical communication means of a second typedisposed in the aperture of said magnetic coupler assembly for opticalcommunication out of the magnetized surface end thereof, and (2) ashield surrounding said magnetic coupler assembly and having a lipextending over the magnetic end surface thereof, said shield surroundingsaid fixed coupler assembly at the face portion thereof to inhibit theentry of ambient light between the face portion and the magnetizedsurface when said fixed and magnetic coupler assemblies, respectively,are magnetically coupled; (c) external communication means connected tothe optical communication means of said second type in said magneticcoupler assembly for electronically communicating information betweenthe electronic circuitry in the meter cover and said externalcommunication means, via the optical communication means of said firstand second types, when said fixed and magnetic coupler assemblies aremagnetically coupled; and (d) means for providing a signal when saidfixed and magnetic coupler assemblies are magnetically coupled, saidmeans comprising a cylindrical slug of a magnetically conductivematerial for concentrating magnetic flux from said magnetic couplerassembly, said slug having a first end which is positioned in said fixedcoupler assembly to engage the magnetized surface of said magneticcoupler assembly, through a slot formed in said shield, upon magneticcoupling of said fixed and magnetic coupler assemblies, and a second endopposite said first end, said second end positioned in proximity toswitch means for switching to an activated position from an unactivatedposition in response to said concentrated magnetic flux.
 27. Apparatusfor establishing a communication link for the transfer of informationcomprising:(a) a first coupler assembly including:(1) a magnet formagnetic attachment to a second coupler assembly, the structure of saidmagnet being characterized by a cylindrical body having a face portionand being further characterized by an aperture extending from the faceportion into said magnet; (2) an optical communication means of a firsttype disposed in the aperture of said magnet for optically communicatingthrough the aperture in the face portion of said magnet; (3) lightshield means for substantially preventing the entry of ambient lightbetween said first and second coupler assemblies when the couplerassemblies are magnetically attached to form an optical communicationlink for the transfer of information; (b) the second coupler assemblyincluding:(1) a housing of magnetically conductive material, thestructure of said housing being characterized by a cylindrical bodyhaving a face portion substantially symmetrical with the face portion ofthe magnet of said first coupler assembly and further characterized byan aperture extending from the face portion into said body; (2) anoptical communication means of a second type disposed in the aperture ofsaid housing for optically communicating through the aperture in theface portion of said housing; (3) means for providing a signal when thecoupler assemblies are magnetically attached to form said opticalcommunication link, said means comprising a cylindrical slug of amagnetically conductive material for concentrating magnetic flux fromsaid magnet, said slug having a first end which is positioned to engagethe face portion of said magnet through a slot formed in said lightshield means upon attachment of said coupler assemblies, and a secondend opposite said first end, said second end positioned in proximity toswitch means for switching to an activated position from an unactivatedposition in response to said concentrated magnetic flux; and (c) means,formed on either of said first and second coupler assemblies, serving toalign the face portions of said magnet and said housing and thus theoptical communication means of said first and said second typesrespectively.
 28. In a meter that is adapted to be linked for eitherelectronic communication with a central data acquisition andtransmission system, or optical communication with a portableprogrammer/reader device via a readily-detachable magnetic couplerassembly having (i) a magnetized surface on one end thereof, (ii) anaperture extending into the coupler assembly from the magnetizedsurface, (iii) optical communication means of a first type disposed insaid aperture for optical communication out of the magnetized surface,and (iv) a surrounding shield having a lip extending over the magnetizedsurface, the following combination comprising:(a) a meter cover, (b)circuitry housed within said cover, said circuitry including data sourceselector means for switching from said electronic communication link tosaid optical communication link upon receipt of an activate signal, (c)a fixed coupler assembly of magnetically inductive material mountedthrough a portion of the cover and having a face portion external of thecover and including an aperture extending into said fixed couplerassembly from the face portion, the fixed coupler assembly being adaptedto magnetically couple with the magnetic coupler assembly and when socoupled to have its face portion positioned immediately adjacent themagnetized surface of the magnetic coupler assembly and in such alocation that the face portion will be surrounded by said shield so thatthe shield will inhibit the entry of ambient light between the faceportion and the magnetized surface, the fixed coupler assembly furthercomprising:(1) optical communication means of a second type disposed inthe aperture of said fixed coupler assembly for optical communicationexternal of the meter cover at the face portion of said fixed couplerassembly, (2) means connecting the optical communication means of saidsecond type to the electronic circuitry for electronically communicatingtherewith, and (3) means responsive to the flux of said magnetizedsurface for generating said activate signal to said circuitry to permitcommunication upon coupling of said detachable coupler assembly to saidfixed coupler assembly.
 29. The meter in accordance with claim 28wherein said activate signal providing means of said fixed couplerassembly comprises:(a) means for concentrating magnetic flux from saidmagnetized surface of said magnetic coupler assembly when said magneticand fixed coupler assemblies are magnetically coupled; and (b) switchmeans switchable to an activated position from an unactivated positionin response to said concentrated magnetic flux.
 30. The meter inaccordance with claim 29 wherein said means for concentrating magneticflux comprises a cylindrical slug of a magnetically conductive materialhaving a first end which is positioned to engage the magnetized surfaceof said magnetic coupler assembly, through a slot formed in the shieldthereof, upon attachment of said magnetic coupler assembly to said fixedcoupler assembly, and a second end, opposite said first end, positionedin proximity to said switch means.
 31. The meter in accordance withclaim 30 wherein said switch means comprises a magnetically operatedreed switch.